JPH0465267B2 - - Google Patents

Abstract

A sealing device for providing the upstream/downstream sealing of a valve comprising a valving member movable inside the bore of a tubular body and comprising at its periphery a sealing surface coming to bear on a sealing packing mounted in the body at the end of the valving stroke. This sealing packing comprises a dynamic annular sealing element and a coronal metal membrane, whose outer edge portion has flat radial part applied axially against a steep side of a shoulder in the bore of the body, for providing static sealing therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sealing device, in particular for creating an upstream/downstream seal of a valve.

In particular, the invention comprises a valve body movable inside a tubular valve body, which valve body is provided with a sealing surface on its outer periphery, which sealing surface is aligned with the main symmetry axis of the sealing seal at the end of the valve travel. After moving tangentially or parallel to the circular seal, it is incorporated into a valve of the type that abuts this circular sealing gasket.

Furthermore, in the reverse assembly, the center hole of the valve body has a substantially conical sealing surface, and the valve body is provided with a packing on its outer periphery, and this packing forms a static seal with the valve body. It is suitable for a valve which forms a dynamic seal with the sealing surface.

Therefore, in these types of valves, the sealing seal must have multiple functions.
That is, this sealing packing must simultaneously function as a static seal, a dynamic seal, and a seal continuity between the static seal and the dynamic seal.

[Conventional technology and problems]

In particular, due to the operating conditions of the valve, a flexible material that can adapt to the surface conditions of the bearing surface of the valve seat so that the sealing seal provides the best seal, and the sealing/seat contact pressure and the fluid pressure to be sealed. The material must be hard and rigid to withstand the mechanical stresses caused by the valve, but at the same time flexible enough to allow relative movement of the valve body/valve chamber without adversely affecting the sealing action. In certain cases, it is not particularly easy to simultaneously achieve the abovementioned sealing functions.

In fact, if the sealing surface of the valve plug is not precisely centered on the dynamic fluid-sealing surface of the plug in the closed position of the valve, the plug will be compressed unevenly, resulting in a uniform distribution over the entire circumference of the plug. A seal cannot be obtained.
Therefore, in areas where the seal is excessively compressed by the valve body, the valve body cannot withstand this overpressure.
On the other hand, in areas diametrically opposite this area, the seal is less secure and high pressure leaks are more likely.

In order to overcome these drawbacks, valves have been developed in which a mechanism is provided for centering the valve body with respect to the sealing packing. This centering mechanism concerns the movement of the valve, or the valve itself.

However, these solutions are complex, uncertain, and significantly increase the cost of the valve.

Also proposed was a sealing ring in the form of a dual flexible metal O-shaped sealing ring. This sealing ring has two sealing structures: a first flexible metal O-type seal ring structure that forms a static seal with the valve body, and a second flexible metal O-type seal ring structure that forms a dynamic seal. These sealing structures are interconnected while at least partially surrounding them to provide sealing continuity between the static and dynamic seals while simultaneously allowing self-centering of the second sealing structure on the sealing surface of the valve body. and a floating reaction ring which is pressed against the region opposite the second sealing structure region against which the sealing surface of the valve body abuts.

This kind of sealing ring has French patent no.
It is publicly known from No. 7722976 and Japanese Patent Application Laid-open No. 177462/1983.

However, sealing rings of the type described above give excellent results, especially when incorporated into valves or valves for operation in conditions (high or low temperatures) where the specifications of conventional elastomeric packings are prohibited.

The present invention has been made in view of the above points, and
The self-centering characteristic of the double-acting flexible metal O-type sealing ring seal has a simple structure that is easy to construct, and significantly reduces the cost of the parts used, the required processing steps, and the installation operation itself. It is an object of the present invention to provide a flow path sealing device for a valve as described above.

[Summary of the invention]

The valve flow passage sealing device of the present invention includes a tubular body having a shoulder with a steeply sloped surface in the center hole, and a valve body having a conical sealing surface on the outer periphery and movably attached to the center hole of the tubular body. an annular dynamic sealing element and an inner edge portion sealingly connected to the annular dynamic sealing element, the annular dynamic sealing element having a low elastic modulus with respect to circumferential tensile stress and an inner diameter substantially equal to the average diameter of the sealing surface of the tubular body; A sealing gasket with which the sealing surface of the tubular body abuts at the end of the valve movement stroke, comprising a metal membrane with an outer edge portion that is crimped onto the steeply sloped surface of the shoulder formed in the center hole of the tubular body and forms a static seal with the shoulder. and a tightening device that uniformly tightens the flat portion of the metal film in the axial direction to form a static seal, and the tightening device forms an annular groove with the steeply inclined surface of the shoulder, and the tightening device forms an annular groove with the steeply inclined surface of the shoulder. between the outer edge portion and the inner edge portion such that the annular dynamic sealing element is radially guided and axially held, and the central portion of the metal membrane imparts radial movement to the annular dynamic sealing element. In a valve passage sealing device having radial elasticity, the annular dynamic sealing element includes an inner annular portion of substantially rectangular cross section formed from a solid metal of substantially Z-shaped cross section; and a substantially conical connecting portion connecting the outer annular portion to the inner annular portion, the metal membrane having an inner edge thereof Therefore, it is constructed by welding the inner annular portion of the annular sealing element to the radial surface opposite to the outer annular portion.

The annular element used in this sealing device plays the role of the second sealing structure described in the above-mentioned French patent etc.
It is designed to act as a reaction ring.

In another particularly preferred embodiment of the invention, the inner edge portion of the metal membrane is curved to define an annular space, inside which a composite material such as carbon, glass, metal or Kepler (trade name) is inserted. An annular element is arranged which is formed at least in part by a ring of resin reinforced with long fibers of. In this method, the relatively radially constant formation of the annular element can be achieved by appropriately selecting the material forming the fiber element depending on its tensile strength or by the number of turns of the coil forming the winding. It has the advantage of being adjustable.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows a valve body 1 incorporating the valve passage sealing device of the invention, the valve body 1 of which has an at least partially cylindrical central hole 2.
The shoulder 3 provided in the center hole 2 has a
A steeply inclined surface 4 located in a plane perpendicular to the axis 5 of the central hole 2 is formed. Further, the chimney-shaped valve 6 of the chimney-shaped valve device is rotatably attached to the valve body 1 by inserting shafts 7 and 8 into horizontal holes 9 and 10 provided in the valve body 1. One of the two shafts, 7, is used to drive the butterfly valve 6.

In this embodiment, the sealing surface 1 of the chimney-shaped valve 6
2 (the surface constituted by the edge of the valve body) has a spherical shape centered on the main axis of symmetry of the butterfly valve 6. Of course, the invention is not limited to this spherical surface, and in practice this shape can be conical, and more generally a rotating cone,
That is, it can be made of a rotation curved surface of a generatrix of an appropriate curve.

In the closed position, the butterfly valve 6 is arranged with its abutment edge 12 substantially aligned with the steeply sloped surface 4 of the shoulder 3 of the valve body 1 .

In FIG. 1, the sealing device used to create a seal upstream and downstream of the valve is not shown. The circular portions designated 13 correspond to the various structural details shown in FIGS. 2-5.

The sealing device shown in FIG.
5, and this metal film 15 has an inner edge portion 16
is fixed to the dynamic annular element 14 by a ring, the outer edge part of which has a radially flat part 17 which is clamped against the steeply inclined side 4 of the shoulder 3 of the central bore of the body 1 to form a static seal. The flat portion 17 of the metal film 15 is tightened by a circular collar 19 . This circular collar 19 consists of thick wings 20, 21 and a relatively thin web 22.
The concave portion of the thin web 22 is located on the wall side of the central hole 2 of the valve body 1.

The wing 20 of the circular collar 19 on the side opposite the shoulder 3 has a central hole 2 extending from one side thereof to the other side.
A series of screw holes parallel to the axis of the wing extend through it, into each of which a screw 23 is screwed, the end of which abuts the other wing 21. The element to be tightened (flat part 17 of membrane 15) is
The outer surface of the wing 21 and the steeply sloped surface 4 of the shoulder 3
It is placed in the space between.

Further, the wings 20 of the circular collar 19 abut against a retainer 24 accommodated in a semicircular groove formed in the center hole 2 of the valve body 1. The surface of the wing 20 in contact with the retainer 24 is tapered (chamfered surface 25), so that the retainer 24 is held in its semicircular annular groove by the radial component of the stress applied by the circular collar 19. Ru. Therefore, by screwing in the screw 23, the circular collar 19 is deformed and slightly opened, and the web 22 acts as an elastic hinge. Wing 20 is retainer 2
Since it is held in the axial direction by screw 2
3 presses the element to be clamped against the steeply inclined surface 4 of the shoulder 3 of the central bore 2 of the valve body 1, for example via an elastic O-seal 29.

The seal used in the sealing device shown in FIG. 2 is an annular sealing element 14 made of solid metal;
This annular sealing element 14 has a substantially Z-shaped cross section. The annular sealing element 14 thus comprises an inner annular part 35 of substantially rectangular cross-section, an outer annular part 36, also rectangular but of smaller dimensions, axially offset on the side opposite the butterfly valve 6; It has a conical portion 37 connecting an inner annular portion 35 and an outer annular portion 36.

In this case, the metal membrane 15 has in its central area a rib 38 oriented in the same direction as the valve body 6 (and therefore in the same direction as the shoulder 3). This metal membrane 15 is welded with its inner edge portion 16 to the radial surface 39 of the inner annular portion 35 of the sealing element 14 opposite the outer annular portion 36 .

Similarly to the above, the inside (flat) of this metal film 15
The edge section 17 is clamped against the steeply inclined surface 4 of the shoulder 3 by the wings 21 of the circular collar 19. This tightening is also carried out by means of an elastic O-shaped sealing ring 29. That is, the tightening device has a circular collar 19 with a stepped profile, which circular collar 19 connects the outer edge portion 17 of the metal membrane 15 to the valve body 1.
A first radial surface provided in the central hole of the shoulder 3 which is clamped to the steeply inclined surface of the shoulder 3 and an annular space partially accommodating the annular sealing element 14 are defined together with the steeply inclined surface of the shoulder 3 and an outer annular portion of the annular sealing element. and an abutment surface 44 against which the outer annular portion 36 abuts the end of the radial travel of the annular sealing element 14 .

In this case, in order to pass the assembly formed by the annular sealing element 14 and the metal membrane 15, the outer surface of the wings 21 of the circular collar 19 has a stepped profile, which together with the steeply sloped surface of the shoulder. A space is formed to accommodate the assembly.

Furthermore, a rib 3 provided at the center of the metal film
8, the steeply sloped surface of the shoulder includes a circular axial recess 41 in its central part.

The sealing device shown in FIG. 2 is movable in the radial direction due to elastic deformation of the metal membrane 15 (due to the presence of ribs 38) with respect to the inner annular portion 35 of the annular element 14 forming a dynamic seal with the butterfly-shaped valve body 6. axially movable through deformation of the conical portion 37 connecting the outer annular portion 36 and the inner annular portion 35 of the annular element 14. For this purpose, the outer annular part 36 of the annular element 14 is held in the axial direction by the radial surface 43 of the wings 21 of the circular collar 19, but can be moved in the radial direction.

Figures 3 to 5 show reference examples of sealing devices incorporated in the valve passage sealing device according to the present invention. In the sealing device shown in Figure 3, the packing used is made of solid metal. an annular sealing element 14 consisting of a rectangular cross-section and a corner 26 in contact with the edge 12 of the valve body 6;
is slightly beveled. In this case, the metal film 15
has a ring shape with a V-shaped curved portion 27 at its center. In this case, the surface of the annular element 14 opposite to the chamfered portion 26 is welded to the inner edge portion 28 of the metal film 14 on the side of the curved portion 27 .
The outer flat edge 17 of the metal film 15 has a circular collar 1
The shoulder 3 of the central hole is
is crimped against the steeply inclined surface 4 to form a static seal.

In the sealing device shown in FIG. 3, such compression is effected by a resilient O-seal 29 partially received in a groove 30 in the outer edge portion of the wing 21 of the circular collar 19. Also, this elasticity O
Compression of the shaped seal 29 causes the wing 21 to press against the circular collar 1 against the small protrusion 31 in the central hole of the valve body 1.
It is limited by the abutment at the tightening angle of 9. The annular element 14 is held in place axially by the axially outer surface 32 of the wings 21 of the circular collar 19 abutting the inner edge portion 28 of the metal membrane 15 on the side opposite the valve 6 .

Of course, a step 33 is provided on the steeply sloped surface of the shoulder 3 so that the curved portion 27 of the metal film 15 and the annular element 14 can be inserted into the wing 21.
It forms an annular space together with the outer surface of.

In the sealing device shown in FIG. 4, the annular sealing element comprises a solid metal ring 46, whereas the metal membrane 15 has a question mark-shaped cross-section and has a curved portion 16 surrounding the ring 46 inside. It is provided. It also has a flat radius portion 17 on the outside thereof, and this radius portion 17 forms the steeply inclined surface 4 of the shoulder 3.
is crimped. These two radius sections 16, 17
are interconnected by a conical link 47. In this case as well, the flat portion 17 is tightened by the circular collar 19, which allows the elastic O-shaped sealing ring 2 to tighten.
Implemented via 9. This seal ring is crimped with the circular collar 1 against the small protrusion 49 of the valve body 1.
9 by the abutment of the edges of the wings 21.

The advantage of this method is that the material of the metal membrane 15 on the one hand and the material of the solid ring 46 on the other hand can be perfectly adapted to the respective functions of these parts (sealing function for the membrane and sealing function for the reaction ring). mechanical functions), which can be easily and independently determined. Due to the simplicity of this method and its low cost of implementation, machining operations on the valve body 1 are carried out to a minimum.

This method differs from the previous method in that it does not include a circular space or a step in the steeply sloped surface of the center hole shoulder 3. Further, this method does not require any special processing of the circular collar wing 21 other than the very shallow step shown in FIG. 4, and this step can be omitted if necessary.

The sealing gasket used in the sealing device shown in FIG. A ring 52 of a composite material, such as resin reinforced with long fibers of boron, glass, carbon, Kevlar or metal, is housed in the annular space. has been done. The fitting of this sealing gasket is carried out in the same manner as described in connection with FIG. be done.

In this regard, the solid metal ring 46 of the packing of FIG. 4 may be replaced by the composite ring of FIG. 5.

The method illustrated in FIGS. 4 and 5 is particularly noteworthy because of the simplicity of the construction of the sealing gasket and the uniqueness of its construction which enhances its flexibility. In fact, depending on the application, these rings 14, 52
By appropriately selecting the material, the radial elasticity can be easily adjusted.

Of course, the invention is not limited to the above structure. In particular, the present invention relates to various combinations which are clearly analogous to these structures, and in particular to a sealing gasket in which the central hole of the valve body includes a substantially conical sealing surface, and which comprises any of the aforementioned gaskets. relates to an inverted assembly mounted on the outer periphery of the valve body. In this case, the sealing seal forms a static seal with the valve body and forms a dynamic seal with the sealing surface of the central hole of the valve body.

It is clear that such a reverse assembly will be obvious to those skilled in the art from the foregoing description.

〔Effect of the invention〕

As described above, according to the present invention, the inner annular portion of the annular element that forms a dynamic seal with the butterfly-shaped valve body has radial movability due to elastic deformation of the metal film;
The outer annular portion of the annular element is held axially but radially movable by deformation of the conical portion connecting the outer annular portion and the inner annular portion of the annular element. is movable and has the effect that the annular element used in the sealing device takes on the role of a second sealing structure and the role of a reaction ring.

[Brief explanation of the drawing]

FIG. 1 is a schematic axial sectional view of a butterfly valve incorporating a sealing device according to the invention, FIG. 2 is a sectional view of a sealing device according to the invention, and FIGS. 3 to 5 are references for the sealing device. It is a figure which shows an example. 1...Valve body, 2...Center hole, 3...Shoulder, 4...
Steeply inclined surface, 6... Valve body, 12... Valve body contact surface, 14
... annular sealing element, 15 ... metal film, 16 ... inner edge of metal film, 17 ... outer edge, 19 ... collar, 29 ... O-shaped seal, 35 ... annular inner part, 36 ... annular outer part, 39 ... radial surface, 43 ... second radial surface, 44... contact surface;

Claims (1)

[Scope of Claims] 1. A tubular body having a shoulder with a steeply sloped surface in the center hole, a valve body having a conical sealing surface on the outer periphery and movably attached to the center hole of the tubular body, and an annular dynamic sealing element having a low modulus of elasticity with respect to tensile stresses of A sealing packing having a metal membrane having an outer edge portion which is crimped onto the steeply inclined surface of the shoulder formed in the hole and forming a static seal together with the shoulder, and which the sealing surface of the tubular body abuts at the end of the valve movement stroke; a tightening device that uniformly tightens the flat portion of the membrane in the axial direction to form a static seal; the tightening device forms an annular groove with the steeply inclined surface of the shoulder; radially elastic between the outer and inner edge portions so that the sealing element is radially guided and axially held and the central part of the metal membrane creates a radial movement of the annular dynamic sealing element. The annular dynamic sealing element 14 includes an inner annular portion 35 of substantially rectangular cross section formed from solid metal of substantially Z-shaped cross section;
an annular outer portion 36 axially offset to the side opposite the valve body with respect to the annular inner portion 35; and a substantially conical connecting portion 37 connecting the outer annular portion 36 to the inner annular portion 35; The metal film 15 is
A valve channel sealing device, characterized in that it is welded by its inner edge 16 to the radial surface 39 of the inner annular part 35 of the annular sealing element 14 opposite the outer annular part 36. 2. The tightening device has a collar 19 with a stepped profile;
This collar 19 has a first radial surface that clamps the outer edge portion 17 of the metal membrane 15 to the steeply inclined surface of the shoulder 3 provided in the central hole of the valve body 1 and an annular space that partially accommodates the annular sealing element 14 on the shoulder 3. a second radial surface 43 defining a steeply inclined surface of the annular sealing element 14 and axially retaining the outer annular portion of the annular sealing element; The flow path sealing device for a valve according to claim 1, characterized in that the valve has a contact surface 44. 3. The central part of the metal film 15 has a rib 38, and the steeply inclined surface of the shoulder is provided with an axial circular recess 41 in the central part for accommodating the rib 38. A channel sealing device for a valve according to item 1 or 2.